Move /src/test to /tests

tests/ui/iterators/iter-step-overflow-debug.rs

@@ -0,0 +1,21 @@
+// run-pass
+// needs-unwind
+// compile-flags: -C debug_assertions=yes
+
+use std::panic;
+
+fn main() {
+    let r = panic::catch_unwind(|| {
+        let mut it = u8::MAX..;
+        it.next().unwrap(); // 255
+        it.next().unwrap();
+    });
+    assert!(r.is_err());
+
+    let r = panic::catch_unwind(|| {
+        let mut it = i8::MAX..;
+        it.next().unwrap(); // 127
+        it.next().unwrap();
+    });
+    assert!(r.is_err());
+}